1. Field of the Invention
The present invention relates to an image formation apparatus of an electrophotographic system and a control method thereof.
2. Related Background Art
Conventionally, an image formation apparatus is composed of a printer controller which develops image code data transmitted from an external equipment such as a host computer or the like into bit data necessary for printing to be performed by a printer and reads internal information of the printer to display the information, and a printer engine control unit, of which an operation is controlled according to an instruction from the printer controller, notifies the internal information of the printer to the printer controller.
In case of performing printing on the basis of image data transmitted from the external equipment, the print controller which develops the image data executes a print instruction to the engine control unit, and the engine control unit which received the print instruction feeds sheets which are on a predetermined sheet feed cassette (a sheet feed tray) through a sheet feed port. When a printable state is prepared by performing initialization of an electrophotographic process, printing is executed on the basis of the image data transmitted from the external equipment while taking a synchronization in a vertical direction (synchronization between image writing to a photosensitive drum and paper feeding) with the printer controller.
In case of continuously printing plural pages, the print controller performs printing operation one page by one page in such order of a transmission of the print instruction, a vertical synchronization, a transmission of the print instruction of a second page and a vertical synchronization of the second page.
However, in the above conventional image formation apparatus, since it is structured that a sheet feed operation of a next page can be started after terminating vertical synchronization processing of the fed sheet, a page interval becomes longer in an image formation apparatus having a long sheet feed transportation path. Therefore, there occurred a problem that the capacity of a maximum throughput essentially possessed by an apparatus itself can not be efficiently exhibited.
The present invention has been made to solve the above problem, and an object is to provide an image formation apparatus which can maximumly exhibit the capacity of the maximum throughput essentially possessed by the apparatus itself without increasing the cost and a control method thereof.
A representative of the image formation apparatus and the control method thereof according to the present invention is an image formation apparatus of an electrophotographic system, comprising:
a sheet feed means for feeding recording sheets one by one;
a transportation means for transporting the recording sheets fed by the sheet feed means to a position where a visualized image formed on a photosensitive drum is transferred to the recording sheet, through a transportation path;
an engine control unit for controlling drives of the sheet feed means and the transportation means; and,
a printer control unit for developing image data and transmitting a print request command to the engine control unit,
wherein the engine control unit has judgment means for judging whether or not the recording sheets can be fed when a print reservation command for plural pages of the sheets was received from the printer control unit prior to the print request command, and the drives of the sheet feed means and the transportation means are controlled to transport the recording sheets to a predetermined position on the transportation path when the judgment means judges that the recording sheets can be fed.
Preferably, a serial communication is performed between the engine control unit and the printer control unit.
Preferably, when it is designated that the sheets are fed from plural sheet feed ports according to the print reservation command for plural pages, the drives of the sheet feed means and the transportation means are controlled to transport the recording sheets from the plural paper feed ports to the lowest-stream position capable of performing printing in order of a print reservation for the plural pages prior to the print request command.
Preferably, when it is designated that the recording sheets are fed from the plural sheet feed ports according to the print reservation command for the plural pages, the drives of the sheet feed means and the transportation means are controlled to transport the recording sheets from the plural sheet feed ports to a stream position more upper than a junction of the most-upper-stream on the transportation path in case of feeding the sheets from the plural sheet feed ports prior to the print request command.
Preferably, when it is designated that the recording sheets are fed from the plural sheet feed ports according to the print reservation command for the plural pages, there equipped a mode for controlling the drives of the sheet feed means and the transportation means to transport the recording sheets from the plural sheet feed ports to the lowest-stream position capable of performing printing in order of the print reservation for the plural pages prior to the print request command, a mode for controlling the drives of the sheet feed means and the transportation, means to transport the recording sheets from the plural sheet feed ports to a stream position more upper than the junction of the most-upper-stream on the transportation path in a case where the sheets were fed from the plural sheet feed ports prior to the print request command, and selection means for selecting one of the both modes.
An image formation apparatus of another aspect according to the present invention being the image formation apparatus of the electrophotographic system, comprises:
a sheet feed means for feeding recording sheets one by one;
a transportation means for transporting the recording sheet fed by the sheet feed means to a transference means for transferring a visualized image formed on a photosensitive drum to the recording sheet, through a transportation path;
an engine control unit for controlling drives of the sheet feed means and the transportation means; and
a printer control unit for developing image data and transmitting a print command for issuing a print instruction and a print reservation command for previously instructing print information such as a sheet feed port, sheet size or the like prior to the print command, to the engine control unit through a serial communication line,
wherein the engine control unit has judgment means for judging whether or not a sheet feed operation of the recording sheets can be performed when the print reservation command for plural pages was received from the printer control unit, and when the judgment means judged that the recording sheets can be fed, drives of the sheet feed means and the transportation means are controlled to transport the recording sheets to a predetermined position on the transportation path.
Preferably, plural sheet feed means are equipped, and the transportation means can be driven or stopped in driving of the transference means,
the predetermined position on the transportation path is more upper than that of the transference means, and a leading edge of the recording sheet is on the lowest-stream position from where the sheet is not transported to the transference means when the transportation means is stopped, and
the drives of the sheet feed means and the transportation means are controlled to feed and transport the recording sheets to the predetermined position on the transportation path in order of reception of the print reservation command, when the engine control unit receives the print reservation command for plural pages to be fed from the plural sheet feed means from the print control unit.
Preferably, plural sheet feed means are equipped, and each of the sheet feed means can be driven or stopped in driving of the transportation means,
the predetermined position on the transportation path is more upper than that of a junction where a transportation path of another sheet feed means is interflowed, and a leading edge of the recording sheet is on the lowest-stream position from where the sheet is not transported to the junction when the sheet feed means is stopped, and
the drives of the sheet feed means and the transportation means are controlled to feed and transport the recording sheets to the predetermined position on the transportation path from all of the sheet feed means reserved in the print reservation command, when the engine control unit receives the print reservation command for plural pages to be fed from the plural sheet feed means from the print control unit.
Preferably, when the engine control unit received the print reservation command for the plural pages to be fed from the plural sheet feed means from the print control unit, there equipped selection means which can select one of control means from first control means for controlling the drives of the sheet feed means and the transportation means to feed and transport the recording sheets to the predetermined position on the transportation path in order of reception of the print reservation command and second control means for controlling the drives of the sheet feed means and the transportation means to feed and transport the recording sheets to the predetermined position on the transportation path from all of the sheet feed means reserved in the print reservation command.
A control method of an image formation apparatus of an electrophotographic system according to the present invention, comprises:
a sheet feed step of feeding recording sheets one by one from sheet feed means;
a transportation step of transporting the recording sheets fed by the sheet feed means to a transference means for transferring a visualized image formed on a photosensitive drum to the recording sheet, through a transportation path;
an engine control step of controlling drives of the sheet feed step and the transportation step by an engine control unit; and
a printer control step of developing image data and transmitting a print command for issuing a print instruction and a print reservation command for previously instructing print information such as a sheet feed port, sheet size or the like prior to the print command, to the engine control unit through a serial communication line by a printer control unit,
wherein the engine control unit judges whether or not a sheet feed operation of the recording sheets can be performed when the print reservation command for plural pages is received from the printer control unit, and when it is judged that the recording sheets can be fed, drives of the sheet feed means and the transportation means are controlled to transport the recording sheets to a predetermined position on the transportation path.
Another image formation apparatus according to the present invention, comprises:
an image formation means for forming images on recording sheets;
a sheet feed means for feeding the recording sheets;
a transportation means for transporting the recording sheets fed by the sheet feed means to the image formation means through a transportation path;
an engine control unit for controlling drives of the sheet feed means and the transportation means; and
a reception means for receiving a print request command transmitted from a printer control unit and a reservation command used in reserving printing prior to the print request command,
wherein the engine control unit has judgment means for judging whether or not the recording sheets for pages corresponding to print reservation can be fed, and the plural recording sheets can be fed before receiving the print request command in accordance with a judgment of the judgment means in a case where the print reservation for plural pages is made by using the reservation command.
Preferably, plural sheet feed means are equipped, and at least one of the sheet feed means and sheet size can be instructed with every one of the recording sheet of each page corresponding to the print reservation from the printer control unit.
Preferably, when the print reservation for plural pages to use the plural sheet feed means is made printing is performed in order of the made print reservation, and the recording sheets are fed every page corresponding to the print reservation at timing of corresponding to information related to the recording sheets of pages previously print reserved.
Preferably, when the print reservation for the plural pages to use the plural sheet feed means is made, printing can be performed in an arbitrary order for the print reserved plural pages, and when the print reservation for the plural pages to use the plural sheet feed means is made, the engine control unit controls feeding and transporting of the recording sheet to the sheet feed means to be used to an upper-stream position of a junction, where a transportation path from the sheet feed means joins a transportation path from another sheet feed means.
Preferably, when the print reservation for the plural pages to use the plural sheet feed means is made, there equipped selection means which selects one of a first mode for performing printing in order of the made print reservation and a second mode for performing printing in an arbitrary order for the print reserved plural pages.
According to the present invention, a high speed image formation can be realized in the image formation apparatus of the electrophotographic system. Even if the transportation path of the recording sheets is designed to have a long path, an achievement of the maximum throughput can be easily realized without increasing the cost.
Other objects and features of the present invention will become apparent from the following detailed description and the attached drawings.